Ok, here's the answer from Para:
Chief Operations Officer at Para-Ordnance informed us that their first vendor for the tritium tubes for their night sights had failed to deliver over 700 sets of them. The vendor claimed that there was a shortage of tritium tubes and that is where the story came about a shortage of tubes. To this day that vendor still has not delivered. Once it became obvious there was a problem Para went looking for another source.
Para chose to go with the best, the industry leader in tritium tubes, Trijicon. But as you can imagine when you have to start all over from scratch with a new vendor it has taken a bit of time. Here is the good news for Para customers even though the new Trijicon tubes are more expensive anyone who has a pistol at Para’s customer service or anyone who still has a $99 coupon will get that price. Para will eat the cost increase.
The first order of Para Night Sights with Trijicon tubes should arrive at the Para USA Customer Service Center this coming Monday, April 7, 2008. The order is large enough to clean up the back order of slides and/or pistols waiting there for night sights. Para USA’s Customer Service Center will make it a priority to install them and get customers back their slides with the new night sights with premium Trijicon tubes in them.